The invention relates to a ventilating arrangement for the crankcase of an internal combustion engine with which crankcase gases are returned to the intake pipe of the engine by way of a venting pipe including an oil separator with an oil return line which is arranged at the front wall of the engine and through which oil separated in the oil separator is returned to the oil pan at the bottom of the crankcase.
Such a ventilating arrangement is known for example from DE OS 21 08 270 which discloses an internal combustion engine with a crankcase from which gases and oil vapors under excess pressure are removed. Such a ventilating arrangement prevents the development of excess pressure and temperatures in the crankcase which could lead to the formation of explosive oil vapor/gas mixtures. For the discharge of the vent gases from the crankcase a venting pipe is provided. However, because of environmental considerations, the vent gases are not discharged to the environment, but are admixed to the intake air and are burnt in the engine. The vent pipe includes an oil separator in which oil particles carried along with the vent gases are collected. The oil collected in the oil separator is returned to the oil pan at the bottom of the crankcase by way of an oil return pipe. The vent pipe, the oil separator and the oil return pipe are arranged on the side outside the engine block and require a relatively large amount of space. Especially the oil return pipe must be assembled from pipes which have to be prepared and interconnected by connecting pieces which is quite expensive and time consuming. Also, assembly errors and wear over long periods of engine operation may lead to troublesome leaks.